Epic: Add Data Source implementation for high level Control API resources

[kavalerov]

Data sources allow Terraform to use information defined outside of Terraform, defined by another separate Terraform configuration, or modified by functions. (https://www.terraform.io/language/data-sources#data-sources)

This can be especially relevant for cases when users don't want to manage Ably via terraform, but want to use information about some aspects of its configuration (especially rules and rule targets) to configure other parts of their systems.

• Implement the "app" data source  #40
• Implement key data source #59
• Implement namespace datasource #60
• Implement queue data source #61
• Decide on datasource structure for integration rules (similar to resources with separate source and target, or unified in one) #62
• Implement AMQP rule datasource #63
• Implement AMQP external rule datasource #64
• Implement Kafka rule datasource #65
• Implement Pulsar rule datasource #66
• Implement Kinesis rule datasource #67
• Implement AWS Lambda rule datasource #68
• Implement AWS SQS rule datasource #69
• Implement HTTP Azure Functions rule datasource #70
• Implement HTTP Cloudflare Worker rule datasource #71
• Implement HTTP Google Cloud Function rule datasource #72
• Implement HTTP IFTTT rule datasource #73
• Implement HTTP Zapier rule datasource #74

┆Issue is synchronized with this Jira Task by Unito

[kavalerov]

Created as one issue for now, but likely need to split up into separate issues per resource when we get to this.

[sync-by-unito]

➤ Automation for Jira commented:

The link to the corresponding Jira issue is https://ably.atlassian.net/browse/SDK-3020